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An irrelevant battle of precision

Citizen Eco-drive versus Seiko Solar - which is more precise?

1w ago


Some time ago in this tribe somebody was talking about the precision of Citizen's Eco-drive movement. Since I own that, and a Seiko's Solar, I decided to run a little experiment.

As experiments go, this one is not very well designed. Firstly, I have only one each, so your mileage may vary. Secondly, I left the watches in their "display" position - which is the one position a watch normally spends little time in (when it's worn, which is when precision matters), so if a watch is regulated at all, it won't be regulated for this position.

I used a Casio radio-synchronized G-Shock as my true time. It gets synch-ed up with an atomic watch that lives somewhere in a bunker over long wave radio every 24h. Which should be as precise as using a GPS. I set the two watches by the G-Shock within one minute of each other on August 10th and left them where they would be exposed to sunlight, but not a lot of heat (that's one mistake I'll not repeat. Don't leave watches on a windowsill) - since all three run on solar power. And I didn't touch them for a month.

Lets see what what came out of that.

The Citizen has run forward by 10 seconds. Which is fine for a Quartz with this price tag. After all, we're not talking about multi-thousand dollar Spring Drive movements here.

But the Seiko! The Seiko is still within a few fractions of a second from the true time. How about that in a few hundred dollar watch that is several years old?

Now, there is much, much more to a watch movement's precision than just keeping decent time while sitting without movement at room temperature. It may very well be that the Citizen will wipe the floor with the Seiko if I wear them both to a class 5 run down freezing Norwegian rivers. Although in that case it's more likely that they'd both die. But at least under these limited conditions, you just got to respect the Seiko Solar movement.

And of course, as I look down at the watch that I'm actually wearing - an automatic that was set to the same true time not two weeks ago - it's easy to see just how much better a Quartz movement really is. Even before we remember that it's also more reliable and maintenance-free.

Retarded by 1:30 in less than two weeks. I though a watch was supposed to keep time for me, not vice versa?

Retarded by 1:30 in less than two weeks. I though a watch was supposed to keep time for me, not vice versa?

Here you go. Now you have an answer to a question you probably never bothered to ask in the first place.

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Comments (8)

  • sun-powered battle : Seiko Solar vs Citizen Eco-Drive @tribe

      8 days ago
  • If the Turtle looses time, put it flat, dial up at night.

    If it gains too much time, put it on its side.

    My turtle is almost as precise as a quartz when worn every day.

    I have set it 2 months ago and it is now +25 seconds.

    Pretty happy with it, much better than my SKX ever was.

      8 days ago
    • interesting, I will try that. I do wear it every day but I store it in the display position for the night - mainly just to see the time. In fact, I'll reset it and do that for a month and see what happens.

      In this class, watches are not regulated I...

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        7 days ago
  • This is brilliant, thankyou!

      8 days ago
  • If I’d left 3-watches in my window; they’d get stolen within a few hours!


      8 days ago
  • This is actually interesting and a good test. I was a little surprised by the results but probably wouldn't have been upon further rumination. It's early I need more coffee. But I really enjoyed this one. Great stuff!

      8 days ago